Recording device and method, computer program, and recording medium

ABSTRACT

A recording apparatus is provided with: a recording device for recording a data pattern onto a recording medium provided with a user data area; a first controlling device for controlling the recording device to record the data pattern for adjusting the recording condition into an area portion which is outer than an end on an outer side of a recording-scheduled area portion and in which the data pattern is scheduled to be recorded; a reading device for reading the data pattern recorded by the control of the first controlling device, thereby obtaining a read signal; a measuring device for measuring jitter of the read signal; an adjusting device for adjusting a recording condition such that the jitter satisfies a desired condition, and a second controlling device for controlling the recording device to start the recording into the recording-scheduled area portion by using the recording condition adjusted by the adjusting device.

TECHNICAL FIELD

The present invention relates to a recording apparatus for and arecording method of recording a data pattern onto a recording medium, acomputer program which makes a computer function as such a recordingapparatus, and the recording medium.

BACKGROUND ART

Optical discs such as a DVD and a Blu-ray disc have been rapidly spread.In such optical discs, a data pattern is recorded onto a recordingsurface by applying a laser beam onto the recording surface. Thus, it isnecessary to perform a recording compensation operation which is anoperation of providing an appropriate strategy of the laser beam (i.e.shape of a recording pulse) in order to perform optimum recording. Apatent document 1 discloses one example of the recording compensationoperation.

On the other hand, various technologies relating to an OPC (OptimumPower Control) which is an operation of providing an appropriate power(specifically, a recording power) of the laser light are proposed,separately from the recording compensation operation which is theoperation of providing the appropriate strategy of the laser beam. Forexample, a patent document 1 discloses a technology in which the OPC isperformed, in a write once type recording medium on which DAO (Disc AtOnce) is performed, by judging an recording amount of a date to berecorded and recording an OPC pattern into an area portion into whichthe data is not recorded.

Patent document 1: Japanese Patent Application Laid Open No. 2000-207742Patent document 2: Japanese Patent Application Laid Open No. 2006-99889

DISCLOSURE OF INVENTION Subject to be Solved by the Invention

However, in the aforementioned recording compensation operation, inprinciple, the recording compensation operation is performed in a PCA(Power Calibration Area) located on the innermost side of the opticaldisc. Moreover, in the case of a relatively high linear velocity whichcannot be realized in the PCA located on the innermost side, generally,the recording compensation operation is performed in a PCA (PowerCalibration Area) located on the outermost side of the optical disc.However, an area portion on the innermost side or outermost side onwhich the PCA is located is relatively away from an area portion inwhich data is actually recorded, so that the properties of the areaportions are not always the same, which is technically problematic. Inparticular, the area portion on the outermost side of the optical dischas such a technical problem that the recording properties likely varywidely in comparison with another area portion. Thus, even if thestrategy is optimized by performing the recording compensation operationin the PCA, the optimized strategy is not necessarily optimal in thearea portion in which the data is actually recorded, which istechnically problematic.

Even in the patent document 2, the power of the laser beam is merelyoptimized by performing OPC, and it has such a technical problem thatthe strategy is not necessarily optimal.

In view of the aforementioned problems, it is therefore an object of thepresent invention to provide, for example, a recording apparatus andmethod which can more preferably optimize the strategy by performing therecording compensation operation in a more preferable aspect, as well asa computer program and a recording medium.

Means for Solving the Subject

The above object of the present invention can be achieved by a recordingapparatus provided with: a recording device for recording a desired datapattern onto a recording medium provided with a user data area; a firstcontrolling device for controlling the recording device to record thedata pattern for adjusting a recording condition of the recording deviceinto an area portion which is outer than an end on an outer side of arecording-scheduled area portion before the data pattern is recordedinto the recording-scheduled area portion which is an area portion inthe user data area and in which the data pattern is scheduled to berecorded by the recording device; a reading device for reading the datapattern recorded by the control of the first controlling device, therebyobtaining a read signal; a measuring device for measuring jitter of theread signal; an adjusting device for adjusting the recording conditionsuch that the jitter measured by the measuring device satisfies adesired condition; and a second controlling device for controlling therecording device to start the recording of the data pattern into therecording-scheduled area portion by using the recording conditionadjusted by the adjusting device.

The above object of the present invention can be also achieved by arecording method in a recording apparatus provided with: a recordingdevice for recording a desired data pattern onto a recording mediumprovided with a user data area, the recording method provided with: afirst controlling process of controlling the recording device to recordthe data pattern for adjusting a recording condition of the recordingdevice into an area portion which is outer than an end on an outer sideof a recording-scheduled area portion before the data pattern isrecorded into the recording-scheduled area portion which is an areaportion in the user data area and in which the data pattern is scheduledto be recorded by the recording device; a reading process of reading thedata pattern recorded by the control of the first controlling process,thereby obtaining a read signal; a measuring process of measuring jitterof the read signal; an adjusting process of adjusting the recordingcondition such that the jitter measured by the measuring processsatisfies a desired condition; and a second controlling process ofcontrolling the recording device to start the recording of the datapattern into the recording-scheduled area portion by using the recordingcondition adjusted by the adjusting process.

The above object of the present invention can be also achieved by acomputer program for recording control and for controlling a computerprovided in a recording apparatus provided with: a recording device forrecording a desired data pattern onto a recording medium provided with auser data area; a first controlling device for controlling the recordingdevice to record the data pattern for adjusting a recording condition ofthe recording device into an area portion which is outer than an end onan outer side of a recording-scheduled area portion before the datapattern is recorded into the recording-scheduled area portion which isan area portion in the user data area and in which the data pattern isscheduled to be recorded by the recording device; a reading device forreading the data pattern recorded by the control of the firstcontrolling device, thereby obtaining a read signal; a measuring devicefor measuring jitter of the read signal; an adjusting device foradjusting the recording condition such that the jitter measured by themeasuring device satisfies a desired condition; and a second controllingdevice for controlling the recording device to start the recording ofthe data pattern into the recording-scheduled area portion by using therecording condition adjusted by the adjusting device, the computerprogram making the computer function as at least one portion of therecording device, the first controlling device, the reading device, themeasuring device, the adjusting device, and the second controllingdevice.

The above object of the present invention can be also achieved by afirst recording medium which is provided with a user data area and onwhich a data pattern is recorded by a recording apparatus provided with:a recording device for recording a desired data pattern onto therecording medium; a first controlling device for controlling therecording device to record the data pattern for adjusting a recordingcondition of the recording device into an area portion which is outerthan an end on an outer side of a recording-scheduled area portionbefore the data pattern is recorded into the recording-scheduled areaportion which is an area portion in the user data area and in which thedata pattern is scheduled to be recorded by the recording device; areading device for reading the data pattern recorded by the control ofthe first controlling device, thereby obtaining a read signal; ameasuring device for measuring jitter of the read signal; an adjustingdevice for adjusting the recording condition such that the jittermeasured by the measuring device satisfies a desired condition; and asecond controlling device for controlling the recording device to startthe recording of the data pattern into the recording-scheduled areaportion by using the recording condition adjusted by the adjustingdevice.

The above object of the present invention can be also achieved by asecond recording medium provided with: a user data area; and a recordingcondition recording area to record therein a recording conditionadjusted by a recording apparatus provided with: a recording device forrecording a desired data pattern onto the recording medium; a firstcontrolling device for controlling the recording device to record thedata pattern for adjusting the recording condition of the recordingdevice into an area portion which is outer than an end on an outer sideof a recording-scheduled area portion before the data pattern isrecorded into the recording-scheduled area portion which is an areaportion in the user data area and in which the data pattern is scheduledto be recorded by the recording device; a reading device for reading thedata pattern recorded by the control of the first controlling device,thereby obtaining a read signal; a measuring device for measuring jitterof the read signal; an adjusting device for adjusting the recordingcondition such that the jitter measured by the measuring devicesatisfies a desired condition; and a second controlling device forcontrolling the recording device to start the recording of the datapattern into the recording-scheduled area portion by using the recordingcondition adjusted by the adjusting device.

The operation and other advantages of the present invention will becomemore apparent from the embodiments explained below.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram conceptually showing the basic structure of arecording apparatus in a first example.

FIG. 2 is a schematic plan view showing the basic structure of anoptical disc and a schematic conceptual view showing a recording areastructure in the radial direction of the optical disc.

FIG. 3 is a flowchart conceptually showing a flow of operations of therecording apparatus in the first example.

FIG. 4 are area structure diagrams conceptually showing an example ofsetting an area portion for performing a recording compensationoperation targeted at an optical disc in which a lead-in area ispre-recorded.

FIG. 5 are area structure diagrams conceptually showing an example ofsetting the area portion for performing the recording compensationoperation targeted at an optical disc in which the lead-in area is notpre-recorded.

FIG. 6 are area structure diagrams conceptually showing another exampleof setting the area portion for performing the recording compensationoperation.

FIG. 7 is a flowchart conceptually showing a flow of the recordingcompensation operation in a step S109 in FIG. 3.

FIG. 8 is a waveform diagram conceptually showing an operation ofmeasuring jitter by an averaging circuit, on a read sample value series.

FIG. 9 is a block diagram conceptually showing the basic structure ofthe averaging circuit.

FIG. 10 is a graph conceptually showing the states of shift jittercomponents in respective data patterns and a shift jitter component as awhole before recording compensation and the states of shift jittercomponents in respective data patterns and a shift jitter component as awhole after the recording compensation.

FIG. 11 is a timing chart conceptually showing a first aspect of arecording strategy adjustment operation.

FIG. 12 is a timing chart conceptually showing a second aspect of therecording strategy adjustment operation.

FIG. 13 is a timing chart conceptually showing a third aspect of therecording strategy adjustment operation.

FIG. 14 is a graph conceptually showing total jitter of the datapatterns recorded without performing the recording compensationoperation and total jitter of the data pattern recorded after therecording compensation operation is performed in an aspect associatedwith the first example.

FIG. 15 is a graph in which jitter and asymmetry are associated with theradial position of the optical disc.

FIG. 16 are graphs conceptually showing a relation between the presenceof a sensitivity change and the jitter and the asymmetry.

FIG. 17 are waveform diagrams conceptually showing the total jitter andasymmetry of the data pattern recorded by the recording apparatus whichdoes not perform the recording compensation operation and the totaljitter and asymmetry of the data pattern recorded by the recordingapparatus which has performed the recording compensation operation in anouter PCA, in association with the radial position of the optical disc.

FIG. 18 is a block diagram conceptually showing the basic structure ofan information recording apparatus in a second example.

FIG. 19 is a block diagram conceptually showing the basic structure ofan information recording apparatus in a third example.

DESCRIPTION OF REFERENCE CODES

-   1, 2, 3 recording apparatus-   10 spindle motor-   11 pickup-   12 HPF-   13 A/D converter-   14 pre-equalizer-   15 limit equalizer-   16 binary circuit-   17 decoding circuit-   18 delay circuit-   19 averaging circuit-   20 pattern judgment circuit-   21 recording strategy setting circuit-   22 CPU-   23 adder-   24 reference level detection device

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, as the best mode for carrying out the present invention, anexplanation will be given on embodiments of the recording apparatus andmethod, the computer program, and the recording medium of the presentinvention.

Embodiment of Recording Apparatus

An embodiment of the information recording apparatus of the presentinvention is a recording apparatus provided with: a recording device forrecording a desired data pattern onto a recording medium provided with auser data area a first controlling device for controlling the recordingdevice to record the data pattern for adjusting a recording condition ofthe recording device into an area portion which is outer than an end onan outer side of a recording-scheduled area portion before the datapattern is recorded into the recording-scheduled area portion which isan area portion in the user data area and in which the data pattern isscheduled to be recorded by the recording device; a reading device forreading the data pattern recorded by the control of the firstcontrolling device, thereby obtaining a read signal; a measuring devicefor measuring jitter of the read signal; an adjusting device foradjusting the recording condition such that the jitter measured by themeasuring device satisfies a desired condition; and a second controllingdevice for controlling the recording device to start the recording ofthe data pattern into the recording-scheduled area portion by using therecording condition adjusted by the adjusting device.

According to the embodiment of the recording apparatus of the presentinvention, by the operation of the recording device, the data patternaccording to the data to be recorded is recorded onto the recordingmedium.

Here, on the recording apparatus of the embodiment, a recordingcompensation operation explained below is performed before the operationof recording the data pattern performed by the recording device.

Firstly, by the operation of the first controlling device, the datapattern for adjusting the recording condition of the recording device isrecorded into the area portion which is outer than the end on the outerside of the recording-scheduled area portion (i.e. into the area portionin the user data area in which the data pattern according to the data tobe recorded is not scheduled to be recorded). In other words, the datapattern for adjusting the recording condition of the recording device isrecorded into the area portion in the user data area in which the datapattern is not scheduled to be recorded.

Then, the data pattern recorded in the area portion which is outer thanthe end on the outer side of the recording-scheduled area portion isread by the operation of the reading device. As a result, the readsignal is obtained. Then, by the operation of the measuring device, thejitter of the read signal is detected. Then, by the operation of theadjusting device, the recording condition (specifically, for example,recording strategy) of the recording device is adjusted such that thedetected jitter satisfies the desired condition. In other words, therecording compensation operation is performed.

After the recording condition is adjusted, the recording of the datapattern into the user data area is actually started by the operation ofthe second controlling device.

By this, the jitter of the read signal obtained by reading the datapattern recorded after the adjustment of the recording conditionsatisfies the desired condition. Therefore, it is possible to improvethe reading quality of the read signal (in other words, recordingquality or reproduction quality).

In particular, in the embodiment, the recording compensation operationcan be performed by recording the data pattern into the area portionwhich is closer to the area portion (i.e. the recording-scheduled areaportion) in the user data area in which the data pattern is actuallyrecorded in comparison with the area portion such as a PCA disposed onthe innermost side or the outermost side. Thus, the properties of thearea portion in which the recording compensation operation is performedare relatively close to the properties of the area portion in which thedata pattern is actually recorded. By this, in comparison with a casewhere the recording compensation operation is performed in the areaportion such as a PCA disposed on the innermost side or the outermostside, the recording condition optimized by the recording compensationoperation is highly likely preferable or optimal even in the areaportion in which the data pattern is actually recorded. In other words,by performing the recording compensation operation in a more preferableaspect, it is possible to optimize the recording condition, morepreferably. Therefore, the data pattern can be preferably recorded intothe user data area by using the recording condition optimized by therecording compensation operation.

Moreover, in the aforementioned background art (particularly, the patentdocument 2), a special data pattern for OPC is recorded. Thus,considering that bringing the area portion, in which the special datapattern is recorded, close to the recording-scheduled area portion maycause a runaway operation if a reproducing apparatus mistakenly readsthe special data pattern, it is not preferable. On the other hand,according to the embodiment, in order to perform the recordingcompensation operation, a normal data pattern is recorded. Thus, even ifthe reproducing apparatus reads the data pattern by bringing the areaportion, in which the normal data pattern is recorded, close to therecording-scheduled area portion, that does not cause the runwayoperation. Even in this regard, according to the embodiment, it ispossible to receive excellent effects in comparison with the backgroundart.

In one aspect of the embodiment of the recording apparatus of thepresent invention, the first controlling device controls the recordingdevice to record the data pattern for adjusting the recording conditioninto an area portion which is outer than the end on the outer side ofthe recording-scheduled area portion and which is in the user data area.

According to this aspect, it is possible to perform the recordingcompensation operation in the area portion in the user data area. Thus,it is possible to bring the properties of the area portion in which therecording compensation operation is performed closer to the propertiesof the area portion in which the data pattern is actually recorded.Therefore, as described above, by performing the recording compensationoperation in a more preferable aspect, it is possible to optimize therecording condition, more preferably.

In another aspect of the embodiment of the recording apparatus of thepresent invention, the first controlling device controls the recordingdevice to record the data pattern for adjusting the recording conditioninto an area portion which is outer than the end on the outer side ofthe recording-scheduled area portion and which is inner than an end onan outer side of the user data area determined in advance inmanufacturing the recording medium.

According to this aspect, the recording compensation operation can beperformed in the area portion assigned as the user data area inmanufacturing the recording medium. Thus, it is possible to bring theproperties of the area portion in which the recording compensationoperation is performed closer to the properties of the area portion inwhich the data pattern is actually recorded. Therefore, as describedabove, by performing the recording compensation operation in a morepreferable aspect, it is possible to optimize the recording condition,more preferably.

In another aspect of the embodiment of the recording apparatus of thepresent invention, the first controlling device controls the recordingdevice to record the data pattern for adjusting the recording conditioninto an area portion which is outer than the end on the outer side ofthe recording-scheduled area portion and which is inner than an end onan outer side of the user data area indicated by a pre-pit or pre-markformed in advance in manufacturing the recording medium.

According to this aspect, the recording compensation operation can beperformed in the area portion assigned as the user data area by the landpre-pit or pre-recorded control information (e.g. control information ina control data zone (CDZ) described later). Thus, it is possible tobring the properties of the area portion in which the recordingcompensation operation is performed closer to the properties of the areaportion in which the data pattern is actually recorded. Therefore, asdescribed above, by performing the recording compensation operation in amore preferable aspect, it is possible to optimize the recordingcondition, more preferably.

In another aspect of the embodiment of the recording apparatus of thepresent invention, the first controlling device controls the recordingdevice to record the data pattern for adjusting the recording conditioninto an area portion which is outer than the end on the outer side ofthe recording-scheduled area portion and which is relatively close tothe end on the outer side of the recording-scheduled area portion.

According to this aspect, it is possible to bring the properties of thearea portion in which the recording compensation operation is performedcloser to the properties of the area portion in which the data patternis actually recorded. Therefore, as described above, by performing therecording compensation operation in a more preferable aspect, it ispossible to optimize the recording condition, more preferably.

In another aspect of the embodiment of the recording apparatus of thepresent invention, the first controlling device controls the recordingdevice to record the data pattern for adjusting the recording conditioninto an area portion which is outer than the end on the outer side ofthe recording-scheduled area portion and which is substantially adjacentto the end on the outer side of the recording-scheduled area portion.

According to this aspect, the recording compensation operation can beperformed in the area portion in the user data area. Thus, it ispossible to bring the properties of the area portion in which therecording compensation operation is performed closer to the propertiesof the area portion in which the data pattern is actually recorded.Therefore, as described above, by performing the recording compensationoperation in a more preferable aspect, it is possible to optimize therecording condition, more preferably.

In another aspect of the embodiment of the recording apparatus of thepresent invention, the first controlling device controls the recordingdevice to record the data pattern for adjusting the recording conditioninto an area portion which is outer than the end on the outer side ofthe recording-scheduled area portion and which is at a position shiftedby a predetermined size from the end on the outer side of therecording-scheduled area portion.

According to this aspect, a predetermined space can be provided betweenthe area portion in which the data pattern for adjusting the recordingcondition is recorded and the recording-scheduled area portion. Thus, itis possible to preferably prevent such a disadvantage that a reproducingapparatus mistakenly reads the data pattern for adjusting the recordingcondition.

In another aspect of the embodiment of the recording apparatus of thepresent invention, the recording medium is further provided with aninner area to record therein the data pattern for adjusting therecording condition, on an inner side of the user data area, and thefirst controlling device controls the recording device to record thedata pattern for adjusting the recording condition into the area portionwhich is outer than the end on the outer side of the recording-scheduledarea portion if the data pattern for adjusting the recording conditioncannot be recorded into the inner area at a predetermined linearvelocity.

According to this aspect, in the case of a relatively high linearvelocity which cannot be realized in the inner area disposed on theinner side (e.g. PCA), it is possible to perform the recordingcompensation operation in the area portion (i.e. the recording-scheduledarea portion) which is closer to the area portion in the user data areain which the data pattern is actually recorded, instead of performingthe recording compensation operation in an outer area disposed on theoutermost side. This eliminates a need to perform the recordingcompensation operation in the area portion on the outermost side inwhich the recording properties may vary widely. As described above, byperforming the recording compensation operation in a more preferableaspect, it is possible to optimize the recording condition, morepreferably.

In another aspect of the embodiment of the recording apparatus of thepresent invention, it is further provided with: an amplitude limitfiltering device for limiting an amplitude level of the read signal byusing a predetermined amplitude limit value, thereby obtaining anamplitude limit signal and for performing a high-frequency emphasisfiltering process on the amplitude limit signal, thereby obtaining anequalization-corrected signal; and a detecting device for detecting thedata pattern of the equalization-corrected signal, the measuring devicemeasuring jitter of the equalization-corrected signal, the adjustingdevice adjusting the recording condition such that the jitter measuredby the measuring device satisfies a desired condition, with reference tothe data pattern detected by the detecting device.

According to this aspect, by the operation of the amplitude limitfiltering device, the amplitude level of the read signal is limited.Specifically, in a signal component of the read signal whose amplitudelevel is greater than an upper limit of the amplitude limit value orwhose amplitude level is less than a lower limit of the amplitude limitvalue, its amplitude level is limited to the upper limit or the lowerlimit of the amplitude limit value. On the other hand, in a signalcomponent of the read signal whose amplitude level is less than or equalto the upper limit of the amplitude limit value or whose amplitude levelis greater than or equal to the lower limit of the amplitude limitvalue, its amplitude level is not limited. As described above, the readsignal whose amplitude level is limited is referred to as the amplitudelimit signal. Moreover, the amplitude limit filtering device performsthe high-frequency emphasis filtering process on the amplitude limitsignal. As a result, the equalization-corrected signal is obtained inwhich the shortest data pattern included in the read signal (e.g. thedata pattern with a run length of 3 T if the information recordingmedium is a DVD, and the data pattern with a run length of 2 T if theinformation recording medium is a is Blu-ray Disc) has an emphasizedamplitude level. In other words, the amplitude limit filtering deviceperforms the same operation as a so-called limit equalizer, on the readsignal.

Then, by the operation of the measuring device, the jitter of theequalization-corrected signal is measured, instead of measuring thejitter of the read signal. In other words, in this aspect, instead ofdirectly using the read signal obtained by reading the data pattern fromthe recording medium to measure the jitter, the equalization-correctedsignal obtained by performing the amplitude limit process and thehigh-frequency emphasis filtering process on the read signal is used tomeasure the jitter.

Moreover, by the operation of the detecting device, the data pattern ofthe equalization-corrected signal is detected. More specifically, it isdetected which run length the data pattern of the equalization-correctedsignal has. The detected data pattern is referred to in the operation ofadjusting the recording condition by the adjusting device.

As described above, the data pattern is detected from theequalization-corrected signal in which the amplitude level of theshortest data pattern is emphasized by the operation of the amplitudelimit filtering device (i.e. limit equalizer). Thus, in any state of theasymmetry of the read signal, it is possible to preferably prevent sucha disadvantage that the shortest data pattern included in the readsignal does not cross a zero level. As a result, the shortest datapattern can be preferably detected. Thus, it is possible to preferablyadjust the recording condition for recording the shortest data pattern.By this, the recording compensation operation can be preferablyperformed with reference to the read signal including the shortest datapattern. In other words, regardless of the state of the asymmetry in theread signal before the recording compensation, the recordingcompensation operation can be preferably performed.

In another aspect of the embodiment of the recording apparatus of thepresent invention, it is further provided with an adding device foradding a predetermined offset signal to the read signal, therebyobtaining an offset-added signal, the measuring device measuring thejitter of the offset-added signal.

According to this aspect, the jitter of the offset-added signal ismeasured. Incidentally, for the offset signal, it is preferable to set asignal which allows the asymmetry of the read signal after the recordingcompensation operation to have a desired value, as occasion demands.Thus, in accordance with the addition of the offset signal, it ispossible to set the asymmetry of the read signal after the recordingcompensation, regardless of the state of the asymmetry before therecording compensation.

In another aspect of the embodiment of the recording apparatus of thepresent invention, the measuring device measures, as the jitter, a shiftjitter component caused by a state of the recorded data pattern fromamong the jitter, and the adjusting device adjusts the recordingcondition such that the shift jitter component as the jitter satisfiesthe desired condition.

According to this aspect, not the random jitter component, which ishardly predicted or which cannot be predicted, but the shift jittercomponent caused by the state of the data pattern which depends on therecording condition is measured. Therefore, by adjusting the recordingcondition, it is possible to preferably perform the recordingcompensation operation such that the shift jitter component satisfiesthe desired condition, relatively easily.

In an aspect of the recording apparatus in which the recording conditionis adjusted such that the shift jitter component satisfies the desiredcondition, as described above, a state in which the jitter satisfies thedesired condition may be a state in which the shift jitter component isless than or equal to a first predetermined value.

By virtue of such construction, it is possible to preferably perform therecording compensation operation so as to reduce the shift jittercomponent.

In an aspect of the recording apparatus in which the recording conditionis adjusted such that the shift jitter component satisfies the desiredcondition, as described above, a state in which the jitter satisfies thedesired condition is a state in which the shift jitter components in aplurality of types of respective data patterns with different runlengths may be substantially same to each other.

By virtue of such construction, it is possible to match the shift jittercomponents in a plurality of types of respective data patterns (e.g. 10types of data patterns with run lengths of 3 T to 11 T and 14 T if theinformation recording medium is a DVD, and 7 types of data patterns withrun lengths of 2 T to 9 T if the information recording medium is aBlu-ray Disc). In other words, instead of narrowing jitter distributionsin the respective data patterns, it is possible to match the averagevalues of the jitter distributions in the respective data patterns (i.e.the shift jitter components). By this, it is possible to perform therecording compensation operation which reduces the jitter, preferablyand relatively easily

In an aspect of the recording apparatus in which the recording conditionis adjusted such that the shift jitter component satisfies the desiredcondition, as described above, a state in which the jitter satisfies thedesired condition may be a state in which a ratio of a random jittercomponent, which is caused by a noise from among the jitter, to thejitter is greater than or equal to a second predetermined value.

The jitter is indicated by the square root of a sum of the square of therandom jitter component and the square of the shift jitter component.Thus, if the random jitter component is greater than the shift jittercomponent (i.e. if the ratio of the random jitter component to thejitter is relatively large), the jitter is hardly reduced even if theshift jitter component is reduced. Therefore, by virtue of suchconstruction, it is possible to perform the recording compensationoperation such that a jitter-reduction effect is preferably achieved bythe adjustment of the recording condition. In other words, it ispossible to preferably avoid the inefficient recording compensationoperation in which the jitter-reduction effect is not preferablyachieved by the adjustment of the recording condition.

In an aspect of the recording apparatus in which the recording conditionis adjusted such that the shift jitter component satisfies the desiredcondition, as described above, the measuring device may measure, as theshift jitter component, an average value in each data pattern of samplevalues of the read signal or the equalization-corrected signal which isthe closest to a zero level point

By virtue of such construction, it is possible to measure the shiftjitter component, preferably and relatively easily.

In an aspect of the recording apparatus in which the recording conditionis adjusted such that the shift jitter component satisfies the desiredcondition, as described above, the adjusting device may preferentiallyadjust the recording condition in recording the data pattern having therelatively large shift jitter component out of a plurality of type ofthe data patterns with different run lengths.

By virtue of such construction, it is possible to reduce the jitter moreefficiently, in comparison with the construction that the recordingcondition in each data pattern is randomly adjusted.

In another aspect of the embodiment of the recording apparatus of thepresent invention, the recording device applies a laser beam, therebyrecording the data pattern, and the recording condition is at least oneof an amplitude and a pulse width of the laser beam or a driving pulsefor driving the laser beam.

By virtue of such construction, it is possible to preferably perform therecording compensation operation by adjusting the amplitude and thepulse width of the driving pulse or the laser beam.

In another aspect of the embodiment of the recording apparatus of thepresent invention, the recording device records the recording conditionadjusted by the adjusting device. In this case, the recording conditionis preferably recorded in association with identification informationfor identifying the information recording apparatus.

According to this aspect, the identification information about therecording apparatus and the recording condition are recorded on therecording medium. Thus, by reading the recording condition, whichcorresponds to the identification information about the recordingapparatus, from the recording medium and by using it as the recordingcondition of the recording device when the data pattern is recorded bythe recording apparatus, it is possible to receive the same variouseffects as those described above, in the recording operation performedon the recording medium, without adjusting the recording conditionagain.

Moreover, even if the recording condition is not recorded on therecording medium for the reason that the recording medium is blank orthe like, in the embodiment, it is possible to preferably perform therecording compensation operation. Moreover, if the resulting recordingcondition is recorded on the recording medium in association with theidentification information about the recording apparatus, it is possibleto receive the same various effects as those described above, in therecording performed on the recording medium, without adjusting therecording condition again next time the data pattern is recorded.

In other words, according to this aspect, without adjusting therecording condition by the adjusting device or with the recordingcondition adjusted at least once, it is possible to receive the samevarious effects as those described above, in the recording performed onthe recording medium, without adjusting the recording condition on thecorresponding recording apparatus again.

Embodiment of Recording Method

An embodiment of the recording method of the present invention is arecording method in a recording apparatus provided with: a recordingdevice for recording a desired data pattern onto a recording mediumprovided with a user data area, the recording method provided with: afirst controlling process of controlling the recording device to recordthe data pattern for adjusting a recording condition of the recordingdevice into an area portion which is outer than an end on an outer sideof a recording-scheduled area portion before the data pattern isrecorded into the recording-scheduled area portion which is an areaportion in the user data area and in which the data pattern is scheduledto be recorded by the recording device; a reading process of reading thedata pattern recorded by the control of the first controlling process,thereby obtaining a read signal; a measuring process of measuring jitterof the read signal; an adjusting process of adjusting the recordingcondition such that the jitter measured by the measuring processsatisfies a desired condition; and a second controlling process ofcontrolling the recording device to start the recording of the datapattern into the recording-scheduled area portion by using the recordingcondition adjusted by the adjusting process.

According to the embodiment of the recording method of the presentinvention, it is possible to receive the same various effects as thosethat can be received by the aforementioned embodiment of the recordingapparatus of the present invention.

Incidentally, in response to the various aspects in the aforementionedembodiment of the recording apparatus of the present invention, theembodiment of the recording method of the present invention can alsoadopt various aspects.

Embodiment of Computer Program

An embodiment of the computer program of the present invention is acomputer program for recording control and for controlling a computerprovided in a recording apparatus provided with: a recording device forrecording a desired data pattern onto a recording medium provided with auser data area; a first controlling device for controlling the recordingdevice to record the data pattern for adjusting a recording condition ofthe recording device into an area portion which is outer than an end onan outer side of a recording-scheduled area portion before the datapattern is recorded into the recording-scheduled area portion which isan area portion in the user data area and in which the data pattern isscheduled to be recorded by the recording device; a reading device forreading the data pattern recorded by the control of the firstcontrolling device, thereby obtaining a read signal; a measuring devicefor measuring jitter of the read signal; an adjusting device foradjusting the recording condition such that the jitter measured by themeasuring device satisfies a desired condition; and a second controllingdevice for controlling the recording device to start the recording ofthe data pattern into the recording-scheduled area portion by using therecording condition adjusted by the adjusting device (i.e. theembodiment of the recoding apparatus of the present invention describedabove (including its various aspects)), the computer program making thecomputer function as at least one portion of the recording device, thefirst controlling device, the reading device, the measuring device, theadjusting device, and the second controlling device.

According to the embodiment of the computer program of the presentinvention, the aforementioned embodiment of the recording apparatus ofthe present invention can be relatively easily realized as a computerreads and executes the computer program from a program storage device,such as a ROM, a CD-ROM, a DVD-ROM, and a hard disk, or as it executesthe computer program after downloading the program through acommunication device.

Incidentally, in response to the various aspects in the aforementionedembodiment of the recording apparatus of the present invention, theembodiment of the computer program of the present invention can alsoadopt various aspects.

An embodiment of the computer program product of the present inventionis a computer program product in a computer-readable medium for tangiblyembodying a program of instructions executable by a computer provided ina recording apparatus provided with: a recording device for recording adesired data pattern onto a recording medium provided with a user dataarea; a first controlling device for controlling the recording device torecord the data pattern for adjusting a recording condition of therecording device into an area portion which is outer than an end on anouter side of a recording-scheduled area portion before the data patternis recorded into the recording-scheduled area portion which is an areaportion in the user data area and in which the data pattern is scheduledto be recorded by the recording device; a reading device for reading thedata pattern recorded by the control of the first controlling device,thereby obtaining a read signal; a measuring device for measuring jitterof the read signal; an adjusting device for adjusting the recordingcondition such that the jitter measured by the measuring devicesatisfies a desired condition; and a second controlling device forcontrolling the recording device to start the recording of the datapattern into the recording-scheduled area portion by using the recordingcondition adjusted by the adjusting device (i.e. the embodiment of therecoding apparatus of the present invention described above (includingits various aspects)), the computer program product making the computerfunction as at least one portion of the recording device, the firstcontrolling device, the reading device, the measuring device, theadjusting device, and the second controlling device.

According to the embodiment of the computer program product of thepresent invention, the aforementioned embodiment of the recordingapparatus of the present invention can be embodied relatively readily,by loading the computer program product from a recording medium forstoring the computer program product, such as a ROM (Read Only Memory),a CD-ROM (Compact Disc-Read Only Memory), a DVD-ROM (DVD Read OnlyMemory), a hard disk or the like, into the computer, or by downloadingthe computer program product, which may be a carrier wave, into thecomputer via a communication device. More specifically, the computerprogram product may include computer readable codes to cause thecomputer (or may comprise computer readable instructions for causing thecomputer) to function as the aforementioned embodiment of the recordingapparatus of the present invention.

Incidentally, in response to the various aspects in the aforementionedembodiment of the recording apparatus of the present invention, theembodiment of the computer program product of the present invention canalso employ various aspects.

Embodiment of Recording Medium

A first embodiment of the recording medium of the present invention is arecording medium which is provided with a user data area and on which adata pattern is recorded by a recording apparatus provided with: arecording device for recording a desired data pattern onto the recordingmedium; a first controlling device for controlling the recording deviceto record the data pattern for adjusting a recording condition of therecording device into an area portion which is outer than an end on anouter side of a recording-scheduled area portion before the data patternis recorded into the recording-scheduled area portion which is an areaportion in the user data area and in which the data pattern is scheduledto be recorded by the recording device; a reading device for reading thedata pattern recorded by the control of the first controlling device,thereby obtaining a read signal; a measuring device for measuring jitterof the read signal; an adjusting device for adjusting the recordingcondition such that the jitter measured by the measuring devicesatisfies a desired condition; and a second controlling device forcontrolling the recording device to start the recording of the datapattern into the recording-scheduled area portion by using the recordingcondition adjusted by the adjusting device.

A second embodiment of the recording medium of the present invention isa recording medium provided with: a user data area; and a recordingcondition recording area to record therein a recording conditionadjusted by a recording apparatus provided with: a recording device forrecording a desired data pattern onto the recording medium; a firstcontrolling device for controlling the recording device to record thedata pattern for adjusting the recording condition of the recordingdevice into an area portion which is outer than an end on an outer sideof a recording-scheduled area portion before the data pattern isrecorded into the recording-scheduled area portion which is an areaportion in the user data area and in which the data pattern is scheduledto be recorded by the recording device; a reading device for reading thedata pattern recorded by the control of the first controlling device,thereby obtaining a read signal; a measuring device for measuring jitterof the read signal; an adjusting device for adjusting the recordingcondition such that the jitter measured by the measuring devicesatisfies a desired condition; and a second controlling device forcontrolling the recording device to start the recording of the datapattern into the recording-scheduled area portion by using the recordingcondition adjusted by the adjusting device. In this case, the recordingcondition is preferably recorded in association with identificationinformation for identifying the information recording apparatus.

According to the embodiments of the recording medium of the presentinvention, the identification information about the recording apparatusand the recording condition are recorded on the recording medium. Thus,by reading the recording condition, which corresponds to theidentification information about the recording apparatus, from therecording medium and by using it as the recording condition of therecording device when the data pattern is recorded by the recordingapparatus, it is possible to receive the same various effects as thosedescribed above, in the recording operation performed on the recordingmedium, without adjusting the recording condition again.

Moreover, even if the recording condition is not recorded on therecording medium for the reason that the recording medium is blank orthe like, in the embodiment, it is possible to preferably perform therecording compensation operation, as described above. Moreover, if theresulting recording condition is recorded on the recording medium inassociation with the identification information about the recordingapparatus, it is possible to receive the same various effects as thosedescribed above, in the recording performed on the recording medium,without adjusting the recording condition again next time the datapattern is recorded.

In other words, according to this aspect without adjusting the recordingcondition by the adjusting device or with the recording conditionadjusted at least once, it is possible to receive the same variouseffects as those described above, in the recording performed on therecording medium, without adjusting the recording condition on thecorresponding recording apparatus again.

Incidentally, the recording condition may be recorded in advance on therecording medium, or it may be recorded along with the recordingoperation, as occasion demands.

Incidentally, in response to the various aspects in the aforementionedembodiment of the recording apparatus of the present invention, each ofthe embodiments of the recording medium of the present invention canalso employ various aspects.

The operation and other advantages of the present invention will becomemore apparent from the examples explained below.

As explained above, according to the embodiment of the recordingapparatus of the present invention, it is provided with the recordingdevice, the first controlling device, the reading device, the measuringdevice, the adjusting device, and the second controlling device.According to the embodiment of the recording method of the presentinvention, it is provided with the first controlling process, thereading process, the measuring process, the adjusting process, and thesecond controlling process. According to the embodiment of the computerprogram of the present invention, it makes a computer function as theembodiment of the recording apparatus of the present invention.According to each of the embodiments of the recording medium of thepresent invention, it is provided with the recording condition recordingarea in which the data pattern is recorded by the aforementionedrecording apparatus or which is to record therein the recordingcondition adjusted by the aforementioned adjusting device. Therefore, byperforming the recording compensation operation in a more preferableaspect, it is possible to optimize the strategy, more preferably.

EXAMPLES

Hereinafter, examples of the present invention will be described withreference to the drawings.

(1) First Example

Firstly, with reference to FIG. 1 to FIG. 17, a first example of therecording apparatus of the present invention will be explained.

(1-1) Basic Structure

Firstly, with reference to FIG. 1, the basic structure of a recordingapparatus in the first example will be described. FIG. 1 is a blockdiagram conceptually showing the basic structure of a recordingapparatus 1 in the first example.

As shown in FIG. 1, the recording apparatus 1 in the first example isprovided with a spindle motor 10, a pickup (PU) 11, a HPF (High PassFilter) 12, an A/D converter 13, a pre-equalizer 14, a binary circuit16, a decoding circuit 17, a delay circuit 18, an averaging circuit 19,a pattern judgment circuit 20, a recording strategy adjustment circuit21, and a CPU 22.

The pickup 11 constitutes one specific example of the “recording device”and the “reading device” of the present invention. The pickup 11photoelectrically converts reflected light when a laser beam LB isapplied to a recording surface of an optical disc 100 rotated by thespindle motor 10, thereby generating a read signal R_(RF). Moreover, thepickup 11 irradiates the recording surface of the optical disc 100 withthe laser beam LB according to a recording strategy set on the recordingstrategy setting circuit 21, thereby recording a data pattern onto theoptical disc 100.

The HPF 12 removes a low-frequency component of the read signal R_(RF)outputted from the pickup 11, and it outputs a resulting read signalR_(HC) to the A/D converter 13.

The A/D converter 13 samples the read signal R_(RF) in accordance with asampling clock outputted from a PLL (Phased Lock Loop) not illustratedor the like, and it outputs a resulting read sample value series RS tothe pre-equalizer 14.

The pre-equalizer 14 removes intersymbol interference which is based ontransmission characteristics in an information reading system which isformed of the pickup 11 and the optical disc 100, and it outputs aresulting read sample value series RS_(C) to the binary circuit 16.

The binary circuit 16 performs a binary process on the read sample valueseries RS_(C), and it outputs a resulting binary signal to each of thedecoding circuit 17 and the pattern judgment circuit 19.

The decoding circuit 17 performs a decoding process or the like on thebinary signal, and it outputs a resulting reproduction signal toexternal reproduction equipment such as a display and a speaker. As aresult, data according to the data pattern recorded on the optical disc100 (e.g. video data, audio data, and the like) is reproduced.

The delay circuit 18 applies a delay corresponding to a time requiredfor the processes of the binary circuit 16 and the pattern judgmentcircuit 20 to the read sample value series RS_(C), and then, it outputsthe read sample value series RS_(C) to the averaging circuit 19. Inother words, by the operations of the delay circuit 18, each samplevalue in the read sample value series RS_(C) outputted from thepre-equalizer 14 is inputted to the averaging circuit 19 in the sametiming as the timing in which the data pattern judgment result of thesample value is inputted.

The averaging circuit 19 constitutes one specific example of the“measuring device” of the present invention. The averaging circuit 19measures the jitter of the read sample value series RS_(C). The detailsof the averaging circuit 19 will be detailed later (refer to FIG. 9).

The pattern judgment circuit 20 constitutes one specific example of the“detecting device” of the present invention. The pattern judgmentcircuit 20 judges the data pattern on the basis of the binary signaloutputted from the binary circuit 16. Namely, it judges which datapattern the binary signal inputted to the pattern judgment circuit 20is. The judgment result is outputted to the averaging circuit 19.

The recording strategy adjustment circuit 21 constitutes one specificexample of the “adjusting device” of the present invention. Therecording strategy adjustment circuit 21 adjusts the recording strategyof each data pattern on the basis of the jitter measured on theaveraging circuit 19.

The CPU 22 constitutes one specific example of the “first controllingdevice” and the “second controlling device” of the present invention.The CPU 22 controls the aforementioned various constituents whichconstitute the recording apparatus 1, thereby controlling the operationsof the recording apparatus 1 as a whole.

(1-2) Optical Disc

Next, with reference to FIG. 2, an explanation will be given on thebasic structure of the optical disc 100 which is the target of therecording operation of the recording apparatus 1 in the first example.FIG. 2 is a schematic plan view showing the basic structure of theoptical disc 100 and a schematic conceptual view showing a recordingarea structure in the radial direction of the optical disc 100.

As shown in FIG. 2, the optical disc 100 has a recording surface on adisc main body, for example, with a diameter of about 12 cm as in a DVD.On the recording surface, the optical disc 100 is provided with a centerhole 101 as the center; an inner PCA (Power Calibration Area) 111 whichconstitutes one specific example of the “inner area” of the presentinvention; a RMA (Recording Management Area) 112; a lead-in area 113; adata recording area 114 which constitutes one specific example of the“user data area” of the present invention; a lead-out area 115; and anouter PCA 116. Moreover, for example, a groove track and a land trackare alternatively provided, spirally or concentrically, centered on thecenter hole 101. Moreover, on the track, the data pattern is divided andrecorded by a unit of ECC block. The ECC block is an error-correctabledata management unit. Moreover, in the example, the optical disc 100 ispreferably a recordable recording medium which can record the datapattern only once.

Then, the groove track is oscillated with a constant amplitude and at aconstant spatial frequency. In other words, the groove track is wobbled,and the cycle of the wobble is set to a predetermined value. On the landtrack, a pit referred to as a land pre-pit (LPP) is formed whichindicates a pre-format address. By virtue of the two addressing (i.e.the wobble and the land pre-pit), it is possible to perform discrotation control during the recording and to generate a recording clock,as well as obtaining information required for the recording of the datapattern, such as a recording address. Incidentally, the pre-formataddress may be recorded in advance by modulating the wobble of thegroove track by a predetermined modulation method, such as frequencymodulation and phase modulation.

Incidentally, in the first example, the optical disc 100 preferablyadopts a ZCLV (Zone Constant Linear Velocity) in which a linear velocityincreases towards the outer side. However, it may adopt another method(e.g. CLU, CAV (Constant Angular Velocity), ZCAV, or the like).

Moreover, as detailed later with reference to FIG. 4 and FIG. 5, thelead-in area 113 of the aforementioned areas may be pre-recorded or maynot be pre-recorded on the optical disc 100 in the first example.

If the lead-in area 113 is pre-recorded, a LRA (Last Recorded Address)which is the address of the end on the outermost side of the datarecording area 114 may be pre-recorded in a CDZ (Control Data Zone) inthe lead-in area 113. In other words, the size of the data recordingarea 114 may be also determined in advance. Moreover, the land pre-pitcan also indicate the LRA. In this case, the LRA pre-recorded in the CDZmatches the LRA indicated by the land pre-pit.

On the other hand, if the lead-in area 113 is not pre-recorded, the sizeof the data recording area 114 may not be determined in advance. In thiscase, after the data pattern is recorded into the data recording area114, the address of the end on the outermost side of an area portion ofthe data recording area 114 in which the data pattern is recorded isrecorded into the CDZ as the LRA. Moreover, the lead-out area 115 isformed to expand to the outer side from the end on the outermost side ofthe area portion in which the data pattern is recorded of the datarecording area 114. On the other hand, even if the lead-in area 113 isnot pre-recorded, the land pre-pit indicates the LRA which is theaddress of the end on the outermost side of the data recording area 114which is default in advance. In this case, the LRA recorded in the CDZmay not match the LRA indicated by the land pre-pit sometimes.

As described above, the position of the end on the outermost side of thedata recording area 114 can vary depending on whether or not the lead-inarea 113 is pre-recorded. In the first example, the explanation will begiven in the condition that an area portion from the end on theoutermost side of the lead-in area 113 to the position indicated by theLRA indicated by the land pre-pit corresponds to one specific example ofthe “user data area” of the present invention. In other words, theexplanation will be given in the condition that the area portion fromthe end on the outermost side of the lead-in area 113 to the positionindicated by the LRA indicated by the land pre-pit corresponds to thedata recording area 114.

Of course, regardless of whether or not the lead-in area 113 ispre-recorded, it is obvious that effects described later can be obtainedby performing operations described later in the case of the optical disc100 having the aforementioned area structure.

(1-3) Operation Example

Next, with reference to FIG. 3, an explanation will be given on anoperation example of the recording apparatus 1 in the first example(particularly, a recording compensation operation). FIG. 3 is aflowchart conceptually showing a flow of operations of the recordingapparatus 1 in the first example.

Firstly, before the data pattern is recorded into the data recordingarea 114 (or before the recording is performed for the first time at acertain linear velocity), by the operation of the CPU 22, it is judgedwhether or not the currently applied linear velocity is a linearvelocity which allows the data pattern for performing the recordingcompensation operation to be recorded in the inner PCA 111 (step S101).

As a result of the judgment in the step S101, if it is judged that thecurrently applied linear velocity is the linear velocity which allowsthe data pattern for performing the recording compensation operation tobe recorded in the inner PCA 111 (the step S101: Yes), the inner PCA 111is set to an area portion for performing the recording compensationoperation (i.e. a recording compensation area) by the operation of theCPU 22 (step S102). Then, OPC is performed in the inner PCA 111 (stepS103). Then, the data pattern is recorded into the recordingcompensation area set in the step S102 by using the laser beam with theoptimum power calculated by the OPC in the step S103, thereby performingthe recording compensation operation (step S109). Incidentally, therecording compensation operation will be detailed later, with referenceto FIG. 7.

On the other hand, as a result of the judgment in the step S101, if itis judged that the currently applied linear velocity is not the linearvelocity which allows the data pattern for performing the recordingcompensation operation to be recorded in the inner PCA 111 (the stepS101: No), then, an area portion required to record the data patternwhich is scheduled to be recorded is calculated by the operation of theCPU 22 (step S104). In other words, the size of the data pattern whichis scheduled to be recorded is calculated. That is, the area portion inwhich the data pattern is scheduled to be recorded is identified fromthe data recording area 114.

Then, by the operation of the CPU 22, it is judged whether or not thereis an area portion in which the data pattern is not recorded in the datarecording area 114, on the basis of the calculation result in the stepS104 (step S105).

As a result of the judgment in the step S105, if it is judged that thereis the area portion in which the data pattern is not recorded in thedata recording area 114 (the step S105: Yes), an area portion of thedata recording area 114 in which the data pattern is not scheduled to berecorded is set to the area portion for performing the recordingcompensation operation (step S106). In other words, the area portion inthe data recording area 114 which is located outer than the end on theouter side of the area portion (i.e. a recording-scheduled area portion)in which the data pattern is scheduled to be recorded and which existsin the data recording area 114 is set to the area portion for performingthe recording compensation operation.

Then, AOPC is performed in the inner PCA 111 (step S108).

Incidentally, the AOPC operation is an operation of calculating theoptimum power of the laser beam LB at a linear velocity which cannot berealized in the inner PCA 111 (e.g. a linear velocity corresponding to arecording speed of 8×) by the OPC operation in the inner PCA 111, inview of a difference in the properties of the recording surface of theoptical disc 100 (e.g. a difference in recording sensitivity on theinner side, on the middle side, and on the outer side), a difference inthe linear velocity, or the like. In other words, it is a special OPCoperation to dissolve such a disadvantage that the OPC is performed inthe inner PCA 111 in which only a relatively low linear velocity can berealized while the linear velocity increases towards the outer side ofthe optical disc 100. According to the AOPC, the recording propertiesthroughout the entire surface of the optical disc 100 can besubstantially estimated on the basis of the result of the OPC performedin the inner PCA 111. Here, considering that the linear velocityincreases towards the outer side of the optical disc 100, it is possibleto substantially estimate the recording properties corresponding to thelinear velocity which can be realized on the optical disc 100, byassociating the radial position of the optical disc 100 with the linearvelocity. As a result, it is possible to estimate the optimum power usedin recording the data pattern into an arbitrary area portion of theoptical disc 100 (in other words, in recording the data pattern at anarbitrary linear velocity). Please refer to International PublicationWO2005/043515 pamphlet for the details.

However, not only the AOPC but also an operation of calculating theoptimum power of the laser beam LB at the linear velocity which cannotbe realized in the inner PCA 111 (e.g. the linear velocity correspondingto a recording speed of 8×) by the OPC operation or an anothercalculation in the inner PCA 111 or the outer PCA 116 can be adopted asthe operation in the step S108. For example, the OPC may be performed ineach of the inner PCA 111 and the outer PCA 116, and from the results ofthe OPC performed in the two PCAs, the optimum power used in recordingthe data pattern into an area portion located between the two PCAs maybe calculated by an interpolation process or the like.

Then, the data pattern is recorded into the recording compensation areaset in the step S106 by using the laser beam with the optimum powercalculated by the AOPC in the step S108, thereby performing therecording compensation operation (step S109).

On the other hand, as a result of the judgment in the step S105, if itis judged that there is not the area portion in which the data patternis not recorded in the data recording area 114 (the step S105: No), thearea portion outer than the data recording area 114 is set to the areaportion for performing the recording compensation operation by theoperation of the CPU 22 (step S107). Then, the AOPC is performed in theinner PCA 111 (step S108). Then, the data pattern is recorded into therecording compensation area set in the step S106 by using the laser beamwith the optimum power calculated by the AOPC in the step S107, therebyperforming the recording compensation operation (step S109).

Here, with reference to FIG. 4 and FIG. 5, the operation of setting thearea portion for performing the recording compensation operation in thestep S106 and the step S107 in FIG. 3 will be explained in more detail.FIG. 4 are area structure diagrams conceptually showing an example ofsetting the area portion for performing the recording compensationoperation targeted at the optical disc 100 in which the lead-in area 113is pre-recorded. FIG. 5 are area structure diagrams conceptually showingan example of setting the area portion for performing the recordingcompensation operation targeted at the optical disc 100 in which thelead-in area 113 is not pre-recorded.

As shown in FIG. 4( a), in the optical disc 100 in which the lead-inarea 113 is pre-recorded, if there is the area portion in which the datapattern is not recorded in the data recording area 114, the area portionof the data recording area 114 in which the data pattern is notscheduled to be recorded is set to the area portion for performing therecording compensation operation. In other words, the area portion (morespecifically, its one portion) which is located outer than the end onthe outer side of the area portion in which the data pattern is recordedand which is located inner than the area portion indicated by the LRApre-recorded in the CDZ is set to the area portion for performing therecording compensation operation.

As shown in FIG. 4( b), in the optical disc 100 in which the lead-inarea 113 is pre-recorded, if there is not the area portion in which thedata pattern is not recorded in the data recording area 114, the areaportion located outer than the data recording area 114 is set to thearea portion for performing the recording compensation operation. Inother words, the area portion (more specifically, its one portion) whichis located outer than the area portion indicated by the LRA pre-recordedin the CDZ is set to the area portion for performing the recordingcompensation operation.

As shown in FIG. 5( a), in the optical disc 100 in which the lead-inarea 113 is not pre-recorded, if there is the area portion in which thedata pattern is not recorded in the data recording area 114, the areaportion of the data recording area 114 in which the data pattern is notscheduled to be recorded is set to the area portion for performing therecording compensation operation. In other words, the area portion (morespecifically, its one portion) which is located outer than the end onthe outer side of the area portion in which the data pattern is recordedand which is located inner than the area portion indicated by the LRAindicated by the land pre-pit (i.e. the LRA assigned to the landpre-pit) is set to the area portion for performing the recordingcompensation operation. In this case, the area portion of the datarecording area 114 in which the data pattern is not scheduled to berecorded is originally padded by using a padding data pattern with alead-out area attribute (e.g. 00h data pattern) or the like, and it istreated as the lead-out area 115 for a reproducing apparatus. In thefirst example, only the area portion of the data recording area 114which is not scheduled to be recorded and which is not used for therecording compensation operation is padded by using the padding datapattern with the lead-out area attribute.

As shown in FIG. 5( b), in the optical disc 100 in which the lead-inarea 113 is not pre-recorded, if there is not the area portion in whichthe data pattern is not recorded in the data recording area 114, thearea portion which is located outer than the data recording area 114 isset to the area portion for performing the recording compensationoperation (more specifically, its one portion). In other words, the areaportion which is located outer than the area portion indicated by theLRA or indicated by the land pre-pit is set to the area portion forperforming the recording compensation operation.

Incidentally, in setting the area portion for performing the recordingcompensation operation in the data recording area 114, the recordingcompensation operation is preferably set in view of a positionalrelation with the end on the outer side of the area portion in which thedata pattern is recorded. Such a setting operation will be explained inmore detail with reference to FIG. 6. FIG. 6 are area structure diagramsconceptually showing another example of setting the area portion forperforming the recording compensation operation.

As shown in FIG. 6( a), the area portion for performing the recordingcompensation operation is preferably set to be relatively close to theend on the outer side of the area portion in which the data pattern isrecorded. In other words, the area portion for performing the recordingcompensation operation is preferably set to be closer to the end on theouter side of the area portion in which the data pattern is recorded,than to the end on the outer side of the data recording area 114pre-recorded in the CDZ or indicated by the LRA indicated by the landpre-pit.

Alternatively, as shown in FIG. 6( b), the area portion for performingthe recording compensation operation is preferably set to adjacent tothe end on the outer side of the area portion in which the data patternis recorded.

However, as shown in FIG. 6( c), the area portion for performing therecording compensation operation is preferably set to be provided withan empty space 117 of a predetermined size (e.g. about 1ECC block toseveral ECC blocks) between the area portion for the recordingcompensation operation and the end on the outer side of the area portionin which the data pattern is recorded.

In FIG. 3 again, after the recording compensation operation, therecording is started at the set linear velocity, under the control ofthe CPU 22 (step S110). In other words, the recording of the datapattern is started by applying the laser beam LB with the optimum powercalculated in the step S103 or the step S108 and in the optimumrecording condition (optimum strategy) set in the step S109. Then, bythe operation of the CPU 22, it is judged whether or not the recordingoperation is to be ended (step S111).

As a result of the judgment in the step S111, if it is judged that therecording operation is to be ended (the step S111: Yes), the recordingoperation is ended.

On the other hand, as a result of the judgment in the step S111, if itis judged that the recording operation is not to be ended (the stepS111: No), then, it is judged whether or not the linear velocity is tobe changed by the operation of the CPU 22 (step S112).

As a result of the judgment in the step S112, if it is judged that thelinear velocity is to be changed (the step S112: Yes), the operationalflow returns to the step S101, and the operations after the step S101are repeated.

On the other hand, as a result of the judgment in the step S112, if itis judged that the linear velocity is not to be changed (the step S112:No), the operational flow returns to the step S111, and the recordingoperation is continued.

Next, with reference to FIG. 7, the recording compensation operation inthe step S109 in FIG. 3 will be explained in more detail. FIG. 7 is aflowchart conceptually showing a flow of the recording compensationoperation in the step S109 in FIG. 3.

As shown in FIG. 7, firstly, under the control of the CPU 22, the datapattern is recorded into the area portion, which is set in the stepS102, the step S106, or the step S107 in FIG. 3, for performing therecording compensation operation (step S201). The data pattern recordedhere is the data pattern for performing the recording compensationoperation but not a special data pattern like the OPC pattern, and it isthe same data pattern as a normal data pattern recorded in the datarecording area 114. Then, the jitter is measured by the operation of theaveraging circuit 19 (step S202).

Now, with reference to FIG. 8 and FIG. 9, an explanation will be givenon the operation in measuring the jitter and the averaging circuit 19for measuring the jitter. FIG. 8 is a waveform diagram conceptuallyshowing an operation of measuring the jitter by the averaging circuit19, on the read sample value series RS_(C). FIG. 9 is a block diagramconceptually showing the basic structure of the averaging circuit 19.

As shown in FIG. 8, in the first example, the averaging circuit 19firstly measures a difference (i.e. an edge shift in an amplitudedirection) between a zero level and a sample value (which is shown by ablack circle in FIG. 8 and which will be hereinafter referred to as a“zero cross sample value” as occasion demands) in the vicinity of thezero cross point of the read sample value series RS_(C), for each datapattern, in order to measure the jitter. If there is no intersymbolinterference in the read signal R_(RF), the sample value thatapproximately matches the zero level in the timing of a clock CLK is thebecomes zero cross sample value. If there is the intersymbolinterference in the read signal R_(RF), the sample value that is theclosest to the zero level in the timing of the clock CLK is the zerocross sample value.

In order to perform such an operation, the averaging circuit 19 isprovided with a trigger generation device 1911, a total jittermeasurement block 191, n individual shift jitter component measurementblocks 192-1 to 192-n, and a whole shift jitter component measurementcircuit 193, as shown in FIG. 9. The number of the individual shiftjitter component measurement blocks 192-1 to 192-n is equal to thecombination number of types of the data patterns. In other words, if theoptical disc 100 is a DVD, there are 10 types of data run lengths (3 Tto 11 T, and 14 T). For each mark length, an individual shift jitter canbe classified by using the combination pattern of front and rear spacelengths. For example, there are 100 combinations of the front spacelength and each mark length, and there are 100 combinations of the rearspace length and each mark: n=200 in total. In view of an effectivepupil diameter and the data run length, the same intersymbolinterference occurs in the combination patterns of the marks/spaces of 6T or more. Thus, if the data of 6 T or more are treated as the samegroup, n can be reduced to n=32. If the optical disc 100 is a Blu-rayDisc, there are 8 types of data run lengths (2 T to 9 T), so that thecombination patterns of the front and rear space lengths for each marklength is n=8*8*2=128 combinations. As in the DVD, in view of theeffective pupil diameter and the data run length, if the data of 5 T ormore are treated as the same group, n can be reduced to n=32. Moreover,each of the individual shift jitter component measurement blocks 192-1to 192-n measures corresponding one of the individual shift jittercomponents in the data patterns.

The read sample value series RS_(C) outputted from the delay circuit 18is inputted to an ABS circuit 1912 and n adders 1923-1 to 1923-n.Moreover, the pattern judgment result outputted from the patternjudgment circuit 20 is inputted to the trigger generation device 1911.

The trigger generation device 1911 generates a trigger signal which isdistinguished in each data pattern and which is at high level (or lowlevel) in timing in which the data pattern is inputted, in accordancewith the pattern judgment result outputted from the pattern judgmentcircuit 20. The trigger signal is inputted to an OR circuit 1917, nsample hold (S/H) circuits 1924-1 to 1924-n, and n counters 1925-1 to1925-n.

Next, the operation of the total jitter measurement block 191 will beexplained. The absolute value of the zero cross sample value outputtedfrom the ABS circuit 1912 is added on an adder 1913. The addition resultis sample-held in timing in which any trigger signal is at high level(or low level) (i.e. in timing in which any data pattern is inputted tothe total jitter measurement block 191), on a sample-holding circuit1914. The result is outputted to a divider 1916 and is fed back to theadder 1913. Thus, a sum of the absolute values of the zero cross samplevalues of all the data patterns is outputted to the divider 1916. On theother hand, a counter 1915 counts the number of times that the triggersignal is at high level (or low level) (i.e. the number of the datapatterns inputted to the total jitter measurement block 191). The countresult is outputted to the divider 1916. The divider 1916 divides thesum of the absolute values of the zero cross sample values by the numberof the data patterns inputted. As a result, an average value of theabsolute values of the zero cross sample values is outputted. In theexample, the average value of the absolute values of the zero crosssample values is a total jitter (i.e. jitter as a whole, which isobtained in consideration of a random jitter component and a shiftjitter component).

Next, the operation of the individual shift jitter component measurementblocks 192-1 to 192-n will be explained. Here, an explanation will begiven on the operation of the individual shift jitter componentmeasurement block 192-1 which corresponds to the zero cross sample valueof the data pattern of a 3 T mark in the rear of a space with a runlength of 3 T when the optical disc 100 is a DVD. By the actions of theadder 1923-1 and the sample-holding circuit 1924-1, in timing in whichthe trigger signal corresponding to the data pattern of the 3 T mark inthe rear of the space with a run length of 3 T is at high level (or lowlevel) (i.e. in timing in which a boundary zero cross sample of the 3 Tmark in the rear of the 3 T space is inputted to the individual shiftjitter component measurement block 192-1), the boundary zero crosssample of the 3 T mark in the rear of the 3 T space is sample-held. Theresult is outputted to a divider 1926-1 and is fed back to the adder1923-1. In other words, on the adder 1923-1, only the boundary zerocross sample value of the 3 T mark in the rear of the 3 T space isintegrated, and a sum of the boundary zero cross sample values of the 3T mark in the rear of the 3 T space is outputted to the divider 1926-1.On the other hand, a counter 1925-1 counts the number of times N(1) thatthe trigger signal is at high level (or low level) (i.e. the number ofthe boundary zero cross samples of the 3 T mark in the rear of the 3 Tspace inputted to the individual shift jitter component measurementblock 192-1). The count result is outputted to the divider 1926-1. Thedivider 1926-1 divides the sum of the boundary zero cross sample valuesof the 3 T mark in the rear of the 3 T space by the inputted N(1). As aresult, an average value S(1) of the boundary zero cross sample valuesof the 3 T mark in the rear of the 3 T space is outputted. Thisoperation is performed for each corresponding data pattern, on the otherindividual shift jitter component measurement blocks 192-2 to 192-n. Inthe example, the average values of the zero cross sample values in therespective data patterns are individual shift jitter components S(1) toS(n).

The individual shift jitter components S(1) to S(n) in the respectivedata patterns are also outputted to the whole shift jitter componentmeasurement circuit 193. Moreover, the number of times N(1) to N(n) thatthe trigger signal is at high level are also outputted to the wholeshift jitter component measurement circuit 193. On the whole shiftjitter component measurement circuit 193, a shift jitter component as awhole obtained in consideration of the occurrence probability of theindividual shift jitter components in the respective data patterns isoutputted by performing an arithmetic operation shown in an Equation 1.

$\begin{matrix}\sqrt{\sum\limits_{i = 1}^{n}{{S(i)}^{2}\frac{N(i)}{\sum\limits_{j = 1}^{n}{N(j)}}}} & \lbrack {{Equation}\mspace{14mu} 1} \rbrack\end{matrix}$

In FIG. 7 again, then, it is judged whether or not the individual shiftjitter components of the jitter measured in the step S202 are less thana first threshold value (step S203). The judgment is performed in eachdata pattern. In other words, the judgment is performed on each of theindividual shift jitter components measured on the individual shiftjitter component measurement blocks 192-1 to 192-n. Specifically, if theoptical disc 100 is a DVD and 6 T or more are treated as the same group,the judgment in the data pattern of a front space with a run length of 3T, the judgment in the data pattern of a front space with a run lengthof 4 T, the judgment in the data pattern of a front space with a runlength of 5 T, and the judgment in the data pattern of a front space ofa run length of 6 T are performed with respect to the 3 T mark. In thesame manner, the judgments in the data patterns of the front spaces withrun lengths of 3 T, 4 T, 5 T, and 6 T or more are performed with respectto marks with 4 T or more. The judgments in the data patterns of rearspaces with run lengths of 3 T, 4 T, 5 T, and 6 T or more are performedwith respect to marks with 3 T, 4 T, 5 T, and 6 T or more. Although 6 Tor more are treated as the unified group, if the recording compensationis performed with respect to an influence of coma aberration or the likeby a tangential tilt, it is possible to treat the influenced datapattern, or individually treat 3 T to 11 T and 14 T. On the other hand,if the optical disc 100 is a Blu-ray Disc and 5 T or more are treated asthe same group, the judgment in the data patterns of front spaces orrear spaces with 2 T, 3 T, 4 T, and 5 T or more is performed withrespect to marks with 2 T, 3 T, 4 T, and 5 T or more. Although 5 T ormore are treated as the unified group, as in the DVD, if the recordingcompensation is performed with respect to the influence of comaaberration or the like by the tangential tilt, it is possible to treatthe influenced data pattern, or individually treat 2 T to 9 T.

Incidentally, a value common to all the data patterns may be used as thefirst threshold value or an individual value for each data pattern (oreach group including a plurality of data patterns) may be used as thefirst threshold value. Moreover, the specific value of the firstthreshold value is preferably set to realize that a ratio of the randomjitter component to the jitter is greater than or equal to apredetermined value (e.g. approximately 80% as described later).Incidentally, the recording compensation operation may be performed suchthat the ratio of the random jitter component to the total jitter isgreater than or equal to approximately 80%. However, in order to furtherreduce the total jitter, the recording compensation operation may beperformed such that the ratio of the random jitter component to thetotal jitter is greater than or equal to approximately 90%.

As a result of the judgment in the step S203, if it is judged that theshift jitter components in at least one or all of the data patterns areless than the first threshold value (the step S203: Yes), the operationis ended.

On the other hand, as a result of the judgment in the step S203, if itis judged that the shift jitter components in at least one or all of thedata patterns are not less than the first threshold value (the stepS203: No), the operation of adjusting the strategy, which is therecording compensation operation, is performed (step S204).

Here, the recording compensation may be performed on the data patterncorresponding to the shift jitter component that is judged not to beless than the first threshold value. Alternatively, in addition to thedata pattern corresponding to the shift jitter component that is judgednot to be less than the first threshold value, the recordingcompensation may be performed on the data pattern corresponding to theshift jitter component that is judged to be less than the firstthreshold value.

Here, with reference to FIG. 10, the recording compensation operation inthe step S204 in FIG. 7 will be explained. FIG. 10 is a graphconceptually showing the states of the shift jitter components in therespective data patterns and the shift jitter component as a wholebefore recording compensation and the states of the shift jittercomponents in the respective data patterns and the shift jittercomponent as a whole after the recording compensation. The average valueof a distribution in each data pattern is the individual shift jittercomponent.

As shown in FIG. 10, in the first example, such a recording compensationoperation is performed that the variations of each of the individualshift jitter components in the respective data patterns is reduced oreliminated. More specifically, if the jitter distributions in therespective data patterns have variations on the basis of the risingpoint of the clock shown by a longitudinal arrow as shown on the leftside of FIG. 10, the recording compensation operation is performed suchthat the jitter distributions in the respective data patterns areshifted to the rising point of the clock as shown on the right side ofFIG. 10. In other words, the recording compensation operation isperformed such that the jitter distributions in the respective datapatterns match at or in the vicinity or the rising point of the clock.In other words, the recording compensation operation is performed suchthat the jitter distributions in the respective data patterns are equal.As a result, the jitter distribution as a whole (i.e. total jitterdistribution) is a normal distribution centered on the rising positionof the clock or the like. Namely, in the recording compensationoperation in the example, instead of reducing the widths of the jitterdistributions in the respective data patterns (in other words, insteadof reducing the random jitter component), the average values of thejitter distributions in the respective data patterns are matched. Thiscorresponds to an operation of reducing the individual shift jittercomponents in the respective data patterns.

In order to reduce the individual shift jitter components in therespective data patterns, the recording strategy adjustment circuit 21adjusts the recording strategy, for example, as shown in FIG. 11 to FIG.13. FIG. 11 is a timing chart conceptually showing a first aspect of therecording strategy adjustment operation. FIG. 12 is a timing chartconceptually showing a second aspect of the recording strategyadjustment operation. FIG. 13 is a timing chart conceptually showing athird aspect of the recording strategy adjustment operation.

For example, as shown in FIG. 11, the pulse width of a recording pulse(i.e. recording strategy) which defines the waveform of the laser beamfor recording the data pattern (record data) may be adjusted.

Moreover, as shown in FIG. 12, the amplitudes (e.g. a top pulseamplitude Po, a middle pulse amplitude Pm, a bottom pulse amplitude Pb)of the recording pulse (i.e. recording strategy) which define thewaveform of the laser beam for recording the data pattern (record data)may be adjusted. Here, as shown in the recording pulse on the top inFIG. 12, the amplitudes of the recording pulse corresponding to the datapatterns with run lengths of 3 T and 4 T and the amplitudes of therecording pulse corresponding to the data patterns with run lengths of 5T or more may be separately adjusted. Alternatively, as shown in thesecond recording pulse from the top in FIG. 12, the amplitudes of therecording pulse corresponding to the data pattern with a run length of 3T, the amplitudes of the recording pulse corresponding to the datapattern with a run length of 4 T, the amplitudes of the recording pulsecorresponding to the data pattern with a run length of 5 T, and theamplitudes of the recording pulse corresponding to the data pattern withrun lengths of 6 T or more may be separately adjusted. Alternatively, asshown in the third recording pulse from the top in FIG. 12, theamplitudes of the recording pulse corresponding to the data pattern witha run length of 3 T, the amplitudes of the recording pulse correspondingto the data pattern with a run length of 4 T, and the amplitudes of therecording pulse corresponding to the data pattern with run lengths of 5T or more may be separately adjusted. Alternatively, as shown in thefourth recording pulse from the top in FIG. 12, the amplitudes of therecording pulse corresponding to the data pattern with a run length of 3T and the amplitudes of the recording pulse corresponding to the datapattern with run lengths of 4 T or more may be separately adjusted.

Moreover, as shown in FIG. 13, even if the recording pulse is not of acastle type, as in the case shown in FIG. 12, the amplitudes of therecording pulse (i.e. the recording strategy) which define the waveformof the laser beam for recording the data pattern for record data) may beadjusted.

Of course, it is obvious that the recording strategy may be adjusted bycombining the adjustment of the pulse width of the recording pulse asshown in FIG. 11 and the adjustment of the amplitudes of the recordingpulse as shown in FIG. 12 and FIG. 13, as occasion demands.

As explained above, according to the recording apparatus 1 in theexample, it is possible to reduce the total jitter by performing therecording compensation operation. Now, with reference to FIG. 14, thereduction effect of the total jitter will be explained. FIG. 14 is agraph conceptually showing total jitter of the data patterns recordedwithout performing the recording compensation operation and total jitterof the data pattern recorded after the recording compensation operationis performed in an aspect associated with the first example.

As shown in the upper part of FIG. 14, the total jitter varies widely onthe recording apparatus which does not perform the recordingcompensation operation. On the other hand, on the recording apparatuswhich performs the recording compensation operation, the total jitter isreduced, and there are small variations or little variation in the totaljitter in comparison with the recording apparatus which does not performthe recording compensation operation.

In particular, the recording compensation operation can be performed inan area portion closer to the area portion in the data recording area114 in which the data pattern is actually recorded in comparison withthe innermost PCA 111 or the outermost PCA 116. Thus, the properties ofthe area portion in which the recording compensation operation isperformed are relatively close to the properties of the area portion inwhich the data pattern is actually recorded. This increases thepossibility that the strategy optimized by the recording compensationoperation is preferable or optimal in the data recording area 114 inwhich the data pattern is actually recorded, in comparison with a casewhere the recording compensation operation is performed in the innermostPCA 111 or the outermost PCA 116. In other words, by performing therecording compensation operation in a more preferable aspect, it ispossible to optimize the strategy, more preferably. Therefore, the datapattern can be recorded into the data recording area 114, morepreferably, by using the strategy optimized by the recordingcompensation operation.

Now, an influence of a change in the properties on the recording surfaceof the optical disc 100 with respect to the jitter or the like will beexplained with reference to FIG. 15 to FIG. 17. FIG. 15 is a graph inwhich the jitter and asymmetry are associated with the radial positionof the optical disc 100. FIG. 16 are graphs conceptually showing arelation between the presence of a sensitivity change and the jitter andthe asymmetry. FIG. 17 are waveform diagrams conceptually showing thetotal jitter and asymmetry of the data pattern recorded by the recordingapparatus which does not perform the recording compensation operationand the total jitter and asymmetry of the data pattern recorded by therecording apparatus 1 which has performed the recording compensationoperation in the outer PCA 116, in association with the radial positionof the optical disc 100.

As shown in FIG. 15, near the outer PCA 116 of the optical disc 100, therecording properties vary widely in comparison with the other areaportion. This is considered to be due to the change in recordingsensitivity caused by a change in thickness of a recording film.

Now, the recording sensitivity in the area portion on the optical discis expressed by percentage (%) on the basis of the recording sensitivityin the middle portion of the optical disc 100 (in other words, near thecenter of the data recording area 114). Here, FIG. 16( a) is a graphshowing a change in the jitter and asymmetry when the data pattern isrecorded into or near a certain area portion (in other words, the areaportion in which the recording compensation operation is performed)after the recording compensation operation is performed in the same areaportion. An area portion with a sensitivity change amount of 0%corresponds to the middle portion of the optical disc 100, and an areaportion with a sensitivity change amount of −10% substantiallycorresponds to the outer PCA 116. In other words, the sensitivity changeamount on the horizontal axis in FIG. 16( a) indicates the change amountof the recording sensitivity in the area portion in which the recordingcompensation operation is performed (or the recording sensitivity in thearea portion in which the data pattern is actually recorded) if themiddle portion of the optical disc 100 is used as the base. As shown inFIG. 16( a), even if there is a sensitivity change on the recordingsurface of the optical disc 100, the jitter does not vary widely whenthe data pattern is recorded into the area portion which is the same asor close to the area portion in which the recording compensationoperation is performed. Specifically, even if the recording compensationoperation is performed in the area portion with a sensitivity changeamount of −10% corresponding to the outer PCA 116, as long as the datapattern is recorded into the outer PCA 116 by using the strategyadjusted there, the jitter is kept approximately 6.5%.

However, when the data pattern is recorded into the area portion whichis different from or away from the area portion in which the recordingcompensation operation is performed, the jitter likely varies widely.FIG. 16( b) is a graph showing a change in the jitter and asymmetry whenthe data pattern is recorded into an area portion with a differencerecording sensitivity from that of an area portion in which therecording compensation operation is performed, after the recordingcompensation operation is performed. In other words, the sensitivitychange amount on the horizontal axis in FIG. 16( b) indicates the changeamount of the recording sensitivity in the area portion in which thedata pattern is actually recorded if the recording sensitivity in thearea portion in which the recording compensation operation is performedis used as the base. As shown in FIG. 16( b), if the recordingcompensation operation is performed in the outer PCA 116 because therecording compensation operation cannot be performed in the inner PCA111, preferable recording cannot be performed in most area portions ofthe data recording area 114 whose recording sensitivity is about 10%different from that of the outer PCA 116. Specifically, if the datapattern is recorded into the data recording area 114 corresponding tothe area portion with a sensitivity change amount of −10% by using thestrategy adjusted in the outer PCA 116 after the recording compensationoperation is performed in the outer PCA 116, the jitter deterioratesabove approximately 11%.

As described above, the fact that the jitter deteriorates if the datapattern is recorded into the data recording area 114 corresponding tothe area portion with a sensitivity change amount of −10% by using thestrategy adjusted in the outer PCA 116 after the recording compensationoperation is performed in the outer PCA 116 is also clear from thegraphs shown in FIG. 17.

In the example, however, if the recording compensation operation cannotbe performed in the inner PCA 111, the recording compensation operationis performed in the data recording area 114. Therefore, in comparisonwith the case where the recording compensation operation is performed inthe innermost PCA 111 or the outermost PCA 116, the strategy optimizedby the recording compensation operation is highly likely preferable oroptimal even in the data recording area 114 in which the data pattern isactually recorded. Thus, even if there is the sensitivity change on therecording surface of the optical disc 100, it is possible to preferablyadjust the strategy and to ensure the preferable recording operation.

Moreover, in the aforementioned background art, the special data patternfor OPC is recorded into the area portion of the data recording area 114in which the data pattern is not scheduled to be recorded. Thus,considering that bringing the area portion in which the special datapattern is recorded close to the area portion in which the data patternis recorded may cause a runaway operation if a reproducing apparatusmistakenly reads the special data pattern, it is not preferable. On theother hand, according to the first example, in order to perform therecording compensation operation, the normal data pattern is recordedinto the area portion of the data recording area 114 in which the datapattern is not scheduled to be recorded. Thus, even if the reproducingapparatus reads the data pattern by bringing the area portion in whichthe normal data pattern is recorded close to the area portion in whichthe data pattern is recorded, that does not cause the runway operation.Even in this regard, according to the first example, it is possible toreceive excellent effects in comparison with the background art.

(2) Second Example

Next, with reference to FIG. 18, a second example of the recordingapparatus of the present invention will be explained. FIG. 18 is a blockdiagram conceptually showing the basic structure of a recordingapparatus 2 in the second example. Incidentally, the same constituentsas those of the aforementioned information recording apparatus 1 in thefirst example will carry the same referential numerals, and theexplanation thereof will be omitted.

As shown in FIG. 18, the recording apparatus 2 in the second example isprovided with a spindle motor 10, a pickup 11, a HPF 12, an A/Dconverter 13, a pre-equalizer 14, a binary circuit 16, a decodingcircuit 17, a delay circuit 18, an averaging circuit 19, a patternjudgment circuit 20, a recording strategy adjustment circuit 21, and aCPU 22, as in the recording apparatus 1 in the first example.

The recording apparatus 2 in the second example is provided particularlywith a limit equalizer 15 between the pre-equalizer 14 and each of thedelay circuit 18 and the binary circuit 16. The limit equalizer 15constitutes one specific example of the “amplitude limit filteringdevice” of the present invention. The limit equalizer 15 performs ahigh-frequency emphasis process on the read sample value series RScwithout increasing the intersymbol interference, and it outputs aresulting high-frequency emphasized read sample value series RS_(H) toeach of the binary circuit 16 and the delay circuit 18. Incidentally,the operations of the limit equalizer 15 are the same as those of aconventional limit equalizer. Please refer to Japanese Patentpublication No. 3459563 for the details.

As a result, the binary circuit 16, the decoding circuit 17, the delaycircuit 18, the averaging circuit 19, the pattern judgment circuit 20,the recording strategy adjustment circuit 21, and the CPU 22 locatedafter the limit equalizer 15 use the high-frequency emphasized readsample value series RS_(H) to perform the operations, instead of theread sample value series RS_(C).

As described above, according to the second example, the patternjudgment is performed as well as performing the recording compensationoperation, by using the output of the limit equalizer 15 (i.e. thehigh-frequency emphasized read sample value series RS_(H)). In otherwords, the pattern judgment is performed as well as performing therecording compensation operation, with the amplitude level of theshortest data pattern emphasized. In any states of the asymmetry of theread signal, it is possible to preferably prevent such a state that theshortest data pattern included in the read signal does not cross thezero level. As a result, the shortest data pattern can be preferablydetected. This preferably allows the recording compensation operation tobe performed with reference to the read signal including the shortestdata pattern. In other words, regardless of the state of the asymmetryin the read signal before the recording compensation, the recordingcompensation operation can be preferably performed.

(3) Third Example

Next, with reference to FIG. 19, a third example of the recordingapparatus of the present invention will be explained. FIG. 19 is a blockdiagram conceptually showing the basic structure of a recordingapparatus 3 in the third example. Incidentally, the same constituents asthose of the aforementioned recording apparatus 1 in the first exampleand the recording apparatus 2 in the second example will carry the samereferential numerals, and the explanation thereof will be omitted.

As shown in FIG. 19, the recording apparatus 3 in the third example isprovided with a spindle motor 10, a pickup 11, a HPF 12, an A/Dconverter 13, a pre-equalizer 14, a limit equalizer 15, a binary circuit16, a decoding circuit 17, a delay circuit 18, an averaging circuit 19,a pattern judgment circuit 20, a recording strategy adjustment circuit21, and a CPU 22, as in the recording apparatus 2 in the second example.

The recording apparatus 3 in the third example is provided particularlywith an adder 23 and a reference level detection circuit 24, each ofwhich constitutes one specific example of the “adding device” of thepresent invention.

The reference level detection circuit 24 outputs a difference betweenthe asymmetry which is actually detected and the asymmetry which istargeted, as offset OFS to the adder 23. On the adder 23, the OFSoutputted from the reference level detection circuit 24 is added to thehigh-frequency emphasized read sample value series RS_(H) outputted fromthe limit equalizer 15. This allows the reference level of thehigh-frequency emphasized read sample value series RS_(H) to be set to apredetermined value.

Incidentally, a signal detected from the read signal on the referencelevel detection circuit 24 is not limited to the aforementionedasymmetry but may be a β value. Alternatively, it may be a partial βvalue indicating the deviation between the amplitude center of the readsignal corresponding to the record data with the shortest run length andthe amplitude center of the read signal corresponding to the record datawith the second shortest run length. Alternatively, it may be an α valueindicating a deviation ratio (or rate) of the amplitude center of theread signal corresponding to the record data with the shortest runlength, with respect to the amplitude center (i.e. the reference level,and the zero level in the example) of the read signals corresponding tothe respective record data with all types of run lengths (e.g. therecord data with each of run lengths of 3 T to 11 T and 14 T if theoptical disc 100 is a DVD, and the record data with each of run lengthsof 2 T to 9 T if the optical disc 100 is a Blu-ray Disc).

By adopting such a structure, the recording apparatus 3 in the thirdexample can change the reference level, thereby arbitrarily setting theasymmetry of the read signal after the recording compensation.Therefore, it is possible to perform the recording compensationoperation which realizes an optimum jitter value and the desiredasymmetry. For example, if the optical disc 100 is a DVD, it is possibleto perform the recording compensation operation which realizes theminimum jitter value and the asymmetry of +5%. In the same manner, ifthe optical disc 100 is a Blu-ray Disc, it is possible to perform therecording compensation operation which realizes the minimum jitter valueand the asymmetry of +2.5%.

Moreover, since the asymmetry of the read signal after the recordingcompensation can be set to a desired value without depending on theasymmetry of the read signal before the recording compensation, it ispossible to perform the good recording compensation operation even ifthe asymmetry varies depending on the individual difference of theoptical disc 100 and the recording apparatus 3.

Moreover, since such construction that the offset corresponding to thedifference between the detected asymmetry and the target asymmetry (i.e.such construction that the desired asymmetry is obtained after therecording compensation by adding the offset to the asymmetry before therecording compensation) is adopted, it is possible to set the asymmetryto the desired value even if the asymmetry before the recordingcompensation varies due to the recording compensation operation which isperformed a plurality of times.

Moreover, since it is unnecessary to adjust the asymmetry by adjustingthe recording power (i.e. the amplitude of the recording pulse), it ispossible to simplify an operation of adjusting a recording condition,and it is also possible to reduce a time required for the operation ofadjusting the recording condition.

Incidentally, in the third example, the recording compensation operationis performed by using the high-frequency emphasized read sample valueseries RS_(H) outputted from the limit equalizer 15. However, from theviewpoint that the asymmetry of the read signal after the recordingcompensation can be set to the desired value, the recording compensationoperation is not necessarily performed by using the high-frequencyemphasized read sample value series RS_(H) outputted from the limitequalizer 15. In other words, even if the recording compensationoperation is performed by using the read sample value series RS_(C)outputted from the pre-equalizer 14, obviously, it is possible toreceive the effect that the asymmetry of the read signal after therecording compensation can be set to the desired value. Therefore, inthe third example, the limit equalizer 15 is not necessarily provided.

Incidentally, the result of the recording compensation operation may berecorded onto the optical disc 100 at each time of the recordingoperation, as occasion demands. Namely, it may be recorded onto theoptical disc 100 when the recording operation is performed by a user, asoccasion demands. Alternatively, it may be recorded on the optical disc100 in advance by using embossed pits, prewriting, or the like, in themanufacturing of the optical disc 100. In this case, it may be recordedin the RMA 112 shown in FIG. 2, a CDZ (Control Data Zone) in the lead-inarea 113, or another area portion. In any cases, the aforementionedeffects can be preferably received. In this case, information indicatingthe result of the recording compensation operation is preferablyrecorded in association with identification information which canidentify the recording apparatus 1 (or 2 or 3) which has performed therecording compensation operation.

As described above, by recording the information indicating the resultof the recording compensation operation and the identificationinformation which can identify the recording apparatus 1 that hasperformed the recording compensation operation onto the optical disc100, it is possible to read the result of the recording compensationoperation corresponding to the identification information about therecording apparatus 1, from the optical disc 100, when the data patternis recorded by the recording apparatus 1. Thus, if the read result ofthe recording compensation operation is used to set the aforementionedrecording condition, it is possible to receive the same various effectsas those described above, in the recording operation performed on theoptical disc 100 without the recording compensation operation.

Moreover, even if the result of the recording compensation operationcorresponding to the identification information about the recordingapparatus 1 is not recorded on the optical disc 100, the same effectscan be appropriately received by reading a result of the recordingcompensation operation corresponding to identification information closeto the identification information about the recording apparatus 1 (inother words, identification information about another recordingapparatus which has a similar property to that of the recordingapparatus 1) and by using the read result of the recording compensationoperation to set the aforementioned recording condition. Alternatively,the same effects can be also appropriately received by performing thesimple recording compensation operation on the basis of the result ofthe recording compensation operation corresponding to the identificationinformation close to the identification information about the recordingapparatus 1.

Moreover, even if the information indicating the result of the recordingcompensation operation is not recorded on the optical disc 100 for thereason that the optical disc 100 is blank or the like, the recordingcompensation operation can be preferably performed by using each of therecording apparatuses in the aforementioned examples. Moreover, if theresulting recording condition is recorded on the optical disc 100 inassociation with the identification information about the recordingapparatus 1, it is possible to receive the same various effects as thosedescribed above, in the recording performed on the optical disc 100,without performing the recording compensation operation again.

In other words, without performing the recording compensation operationor with the recording compensation operation performed at least once, itis possible to receive the same various effects as those describedabove, in the recording performed on the optical disc 100, withoutperforming the recording compensation operation on the correspondingrecording apparatus 1. Therefore, it is possible to reduce the number oftimes that the recording compensation operation is performed, therebysaving an area required for the recording compensation operation.

The present invention is not limited to the aforementioned examples, butvarious changes may be made, if desired, without departing from theessence or spirit of the invention which can be read from the claims andthe entire specification. A recording apparatus and method, a computerprogram, and a recording medium, all of which involve such changes, arealso intended to be within the technical scope of the present invention.

1-17. (canceled)
 18. A recording apparatus comprising: a recordingdevice for recording a desired data pattern onto a recording mediumcomprising a user data area; a first controlling device for controllingthe recording device to record the data pattern for adjusting arecording condition of the recording device into an area portion whichis outer than an end on an outer side of a recording-scheduled areaportion before the data pattern is recorded into the recording-scheduledarea portion which is an area portion in the user data area and in whichthe data pattern is scheduled to be recorded by the recording device; areading device for reading the data pattern recorded by the control ofthe first controlling device, thereby obtaining a read signal; ameasuring device for measuring jitter of the read signal; an adjustingdevice for adjusting the recording condition such that the jittermeasured by the measuring device satisfies a desired condition; and asecond controlling device for controlling the recording device to startthe recording of the data pattern into the recording-scheduled areaportion by using the recording condition adjusted by the adjustingdevice.
 19. The information recording apparatus according to claim 18,wherein the first controlling device controls the recording device torecord the data pattern for adjusting the recording condition into anarea portion which is outer than the end on the outer side of therecording-scheduled area portion and which is in the user data area. 20.The information recording apparatus according to claim 18, wherein thefirst controlling device controls the recording device to record thedata pattern for adjusting the recording condition into an area portionwhich is outer than the end on the outer side of the recording-scheduledarea portion and which is inner than an end on an outer side of the userdata area determined in advance in manufacturing the recording medium.21. The information recording apparatus according to claim 18, whereinthe first controlling device controls the recording device to record thedata pattern for adjusting the recording condition into an area portionwhich is outer than the end on the outer side of the recording-scheduledarea portion and which is inner than an end on an outer side of the userdata area indicated by a pre-pit or pre-mark formed in advance inmanufacturing the recording medium.
 22. The information recordingapparatus according to claim 18, wherein the first controlling devicecontrols the recording device to record the data pattern for adjustingthe recording condition into an area portion which is outer than the endon the outer side of the recording-scheduled area portion and which isrelatively close to the end on the outer side of the recording-scheduledarea portion.
 23. The information recording apparatus according to claim18, wherein the first controlling device controls the recording deviceto record the data pattern for adjusting the recording condition into anarea portion which is outer than the end on the outer side of therecording-scheduled area portion and which is substantially adjacent tothe end on the outer side of the recording-scheduled area portion. 24.The information recording apparatus according to claim 18, wherein thefirst controlling device controls the recording device to record thedata pattern for adjusting the recording condition into an area portionwhich is outer than the end on the outer side of the recording-scheduledarea portion and which is at a position shifted by a predetermined sizefrom the end on the outer side of the recording-scheduled area portion.25. The information recording apparatus according to claim 18, whereinthe recording medium further comprises an inner area to record thereinthe data pattern for adjusting the recording condition, on an inner sideof the user data area, and the first controlling device controls therecording device to record the data pattern for adjusting the recordingcondition into the area portion which is outer than the end on the outerside of the recording-scheduled area portion if the data pattern foradjusting the recording condition cannot be recorded into the inner areaat a predetermined linear velocity.
 26. The information recordingapparatus according to claim 18, further comprising: an amplitude limitfiltering device for limiting an amplitude level of the read signal byusing a predetermined amplitude limit value, thereby obtaining anamplitude limit signal and for performing a high-frequency emphasisfiltering process on the amplitude limit signal, thereby obtaining anequalization-corrected signal; and a detecting device for detecting thedata pattern of the equalization-corrected signal, the measuring devicemeasuring jitter of the equalization-corrected signal, the adjustingdevice adjusting the recording condition such that the jitter measuredby the measuring device satisfies a desired condition, with reference tothe data pattern detected by the detecting device.
 27. The informationrecording apparatus according to claim 18, further comprising an addingdevice for adding a predetermined offset signal to the read signal,thereby obtaining an offset-added signal, the measuring device measuringthe jitter of the offset-added signal.
 28. The information recordingapparatus according to claim 18, wherein the measuring device measures,as the jitter, a shift jitter component caused by a state of therecorded data pattern from among the jitter, and the adjusting deviceadjusts the recording condition such that the shift jitter component asthe jitter satisfies the desired condition.
 29. The informationrecording apparatus according to claim 18, wherein a state in which thejitter satisfies the desired condition is a state in which the shiftjitter component is less than or equal to a first predetermined value.30. The information recording apparatus according to claim 28, wherein astate in which the jitter satisfies the desired condition is a state inwhich the shift jitter components in a plurality of types of respectivedata patterns with different run lengths are substantially same to eachother.
 31. A recording method in a recording apparatus comprising: arecording device for recording a desired data pattern onto a recordingmedium comprising a user data area, the recording method comprising: afirst controlling process of controlling the recording device to recordthe data pattern for adjusting a recording condition of the recordingdevice into an area portion which is outer than an end on an outer sideof a recording-scheduled area portion before the data pattern isrecorded into the recording-scheduled area portion which is an areaportion in the user data area and in which the data pattern is scheduledto be recorded by the recording device; a reading process of reading thedata pattern recorded by the control of the first controlling process,thereby obtaining a read signal; a measuring process of measuring jitterof the read signal; an adjusting process of adjusting the recordingcondition such that the jitter measured by the measuring processsatisfies a desired condition; and a second controlling process ofcontrolling the recording device to start the recording of the datapattern into the recording-scheduled area portion by using the recordingcondition adjusted by the adjusting process.
 32. A computer program forrecording control and for controlling a computer provided in a recordingapparatus comprising: a recording device for recording a desired datapattern onto a recording medium comprising a user data area; a firstcontrolling device for controlling the recording device to record thedata pattern for adjusting a recording condition of the recording deviceinto an area portion which is outer than an end on an outer side of arecording-scheduled area portion before the data pattern is recordedinto the recording-scheduled area portion which is an area portion inthe user data area and in which the data pattern is scheduled to berecorded by the recording device; a reading device for reading the datapattern recorded by the control of the first controlling device, therebyobtaining a read signal; a measuring device for measuring jitter of theread signal; an adjusting device for adjusting the recording conditionsuch that the jitter measured by the measuring device satisfies adesired condition; and a second controlling device for controlling therecording device to start the recording of the data pattern into therecording-scheduled area portion by using the recording conditionadjusted by the adjusting device, the computer program making thecomputer function as at least one portion of the recording device, thefirst controlling device, the reading device, the measuring device, theadjusting device, and the second controlling device.
 33. A recordingmedium which comprises a user data area and on which a data pattern isrecorded by a recording apparatus comprising: a recording device forrecording a desired data pattern onto the recording medium; a firstcontrolling device for controlling the recording device to record thedata pattern for adjusting a recording condition of the recording deviceinto an area portion which is outer than an end on an outer side of arecording-scheduled area portion before the data pattern is recordedinto the recording-scheduled area portion which is an area portion inthe user data area and in which the data pattern is scheduled to berecorded by the recording device; a reading device for reading the datapattern recorded by the control of the first controlling device, therebyobtaining a read signal; a measuring device for measuring jitter of theread signal; an adjusting device for adjusting the recording conditionsuch that the jitter measured by the measuring device satisfies adesired condition; and a second controlling device for controlling therecording device to start the recording of the data pattern into therecording-scheduled area portion by using the recording conditionadjusted by the adjusting device.
 34. A recording medium comprising: auser data area; and a recording condition recording area to recordtherein a recording condition adjusted by a recording apparatuscomprising: a recording device for recording a desired data pattern ontothe recording medium; a first controlling device for controlling therecording device to record the data pattern for adjusting the recordingcondition of the recording device into an area portion which is outerthan an end on an outer side of a recording-scheduled area portionbefore the data pattern is recorded into the recording-scheduled areaportion which is an area portion in the user data area and in which thedata pattern is scheduled to be recorded by the recording device; areading device for reading the data pattern recorded by the control ofthe first controlling device, thereby obtaining a read signal; ameasuring device for measuring jitter of the read signal; an adjustingdevice for adjusting the recording condition such that the jittermeasured by the measuring device satisfies a desired condition; and asecond controlling device for controlling the recording device to startthe recording of the data pattern into the recording-scheduled areaportion by using the recording condition adjusted by the adjustingdevice.